Working On Wilbur

August 4, 2017

Welcome to the "hands on" post about Wilbur.  In the previous Wilbur post is a high level overview of what we did to him, and in this post I will go into details about how we actually did it.  This is definitely not comprehensive (since I personally didn't install the bumpers, sliders, etc), but is focused on the things which I personally took a hand in creating.

 

I will be writing this in a way that may be helpful to other people if they are trying to do something similar to their own vehicle, and as a way to record what I did for my own purposes in the future when I've forgotten the specifics.  There are two main projects about which I'll write.

 

1) Drawer platform extension and 2) electrical system (isolated second battery, solar panels, charge controller, etc).

 

1) Drawer platform extension.  

 

This is the easiest to explain and was also easiest to do.  The purpose was twofold; extend the platform so we could sleep on it comfortably and create additional storage space.  We could have created the entire drawer system ourselves, but this would have taken a significantly longer period of time and I was satisfied with the price and quality level of the Outback drawers.

 

Though I had an end goal in mind from the very beginning before we even purchased the vehicle, there wasn't any specific design created (outside of my head) by the time we started working on the frame.  My best friend had very graciously offered to visit and help me install the drawers and build the frame, and along with the help of my father I knew this was going to end up well.

 

Unfortunately the time we choose to do this was not exactly the smartest.  It was the middle of January and in Walla Walla this meant snow on the ground and temperatures hovering in the teens during the (limited) daytime.  Not the best time to work with metal or outdoors, and we needed to do both.  Oh, and we decided to try and accomplish it all on a single weekend.

 

The drawers were rather straightforward so we started with those.  There's not a lot to be said; we opened the boxes, read the directions and they were installed a few hours later.  This included multiple trips indoors to warm up our freezing appendages.  After the drawers were done we retired inside to lubricate our brains and design the extended platform frame and top.

 

We considered materials for the additional frame and finally decided on aluminum when we were in Home Depot.  It wasn't cheap (about $120 for all the L shaped pieces we used) but the weight, strength and immunity to humidity and other temperature changes was hard to beat.  It's also rather easy to work with.  We used all stainless steel nuts, bolts and washers.  Altogether this was another $20 or so from the local hardware store.  Plus another $20 or so in rubber washers to prevent noise and vibration.  The lid was built from 3/4" Russian birch.  The 4'x8' piece was about $30.

 

All of the material purchased, we retired to the basement to play pool, drink beer and get warm.  We would start building tomorrow.

 

Starting neither bright (overcast) or early (we decided to eat a large breakfast first) the next morning, we began with measuring (three times) and cutting (thankfully just once) all of the L-shaped aluminum.  We argued a bit about how to connect it to the frame of Wilbur, and in the end we decided on the simplest route possible; bolt the cross members to the existing bolts where the 2nd row of seating was mounted.  I feel this was best since we didn't make any permanent changes to the interior of the vehicle.  The drawers and extended platform could be taken out and the seats put back in with no impact to any aspect of the vehicle. 

 

After the aluminum was measured, cut, drilled and edges filed, we bolted everything in place.  In some ways this was actually the most difficult part, given the dimensions of the space we had to work with and how we needed to angle the drill to get the bolts tightened.  We are all also rather tall guys, so there was some swearing and a few drops of blood spilled.  Getting the metal frame in place took about four hours total.   A single person could do it in probably six hours, since a lot of the time was spent with discussions and I confess I did a lot of "supervising" during the process.  It's hard to fit three guys in the truck, okay?

 

Once all the metal was in place, we measured and cut the plywood for the "lids" on top of the frame.  And realized we didn't have the carpet or glue to finish them and it was getting late on Sunday, so we decided to call it for the night.  More beer and pool (and inside where it was warm!).  Later that week, I bought the glue ($15) and automotive carpet ($8) and spent a couple of hours (mostly letting the glue dry) finishing putting the carpet on and then attached the interior 1"x2" shims on the bottom of the lids to hold it in place on top of the frame.  Finally there was another delay while we had to wait for the correct sized aluminum square-U shaped brackets ($16) to arrive so we could screw them on the edges of the lids.  All done!

 

 

All in all, the frame extension cost about $250 and close to fifteen hours of labor (working with lots of breaks and planning).  I could have done it for half the price if I had chosen to go with wood instead of aluminum.  It would also take at least half and probably a third of the time if I did it again, since the design is actually pretty simple and just requires a lot of measuring and careful cutting.  Doing it during a non-freezing time of the year is also a good idea, though it may require more beer.

 

 

2) Electrical system (isolated second battery, solar panels, charge controller, etc).

 

Now we move on to #2, the electrical system (isolated second battery, solar panels, charge controller, etc).  I am going to separate the work in this section into three sub-sections; A) under the hood, B) solar panel installation and wiring and C) hooking everything together with the charge controller.  The actual work on the electrical spanned a couple of months due to design work, parts arriving, Wilbur's t-bone accident requiring him to be in the shop for a while, personal travel and a few other things.

 

To start with, the basics of our design started with an excellent (and extraordinarily long) thread at the expedition portal message board.  I'll save you the tens of hours my dad (who helped me immensely on this project and has a lot of professional electrician experience, though in airplanes and homes instead of vehicles) spent reading this and summarize the design goal for you.

 

First, I wanted to keep it as simple as possible.  Less work to do, less things to break on the road, safer and easier to fix.  I was willing to pay a bit extra for simplicity.

 

Second, over-engineer the crap out of it.  I did not want to ever run out of power.  I mean, what if we wanted to play a game on our phones or watch a movie and couldn't?  Unacceptable.  Plus it would be bad if our fridge ("Freezy" we call him) runs out of power and our food spoils, I suppose.

 

With those two goals, we ended up with a pretty straight forward design.  It is a two-battery system where the second battery is completely isolated via a 500Amp isolator, managed by a racing style switch mounted on the 2nd battery tray by the isolator. The second battery can be joined to the primary electrical circuit for charging or starting as needed, but by default it is isolated. The two solar panels are paired and are wired through the hood into the charge controller under the glove box. Then the controller is hooked into our main battery, an X2 AGM deep cycle model (which is actually a re-branded Northstar model) that has enough CCA to also serve as our starting battery. The concept is the second battery is there in case something happens to the first one, but otherwise everything (including fridge, AC inverter, our laptops, etc) runs off the standard vehicle electrical system, supported by a high-performance battery and our way-too-big solar charging setup. The last item is a small wiring modification to the fuse box which allows the 12v outlets in the truck to be active without requiring the key to be in the ignition (i.e. always on).

 

#2-A, under the hood.

 

The Slee extra battery tray was installed when we started.  The first step was wiring 0-gauge wire along the back of the engine compartment (using existing bolts to attach our mounts) from the primary battery to the second battery tray.  This was welding wire, which has a lot of strands compared to normal electrical wire and made it a bit more flexible and frankly, cheaper.  It cost about $60 for 30' (WAY too much, we needed about 20').  The in-line fuses, fuse-holder and heavy duty connectors were another $30.  Measuring, cutting and connecting it took about an hour.  All of the "live" (i.e. positive, current-carrying) wires are fused between each connection.  Better safe than sorry.

 

 

The next step was putting the shorter connections between the isolator and the second battery.  We mounted almost everything to the Slee 2nd battery tray, it was very handy to keep things tidy and easily accessible.  We also used a few zip ties.

 

 

Then we needed to find a way to get access through the firewall.  Considering many options, we finally ended up at the rather obvious; an existing loom that carried all of the other electrical wires through the firewall and into the compartment behind the glove box.  The loom itself was rather tightly wound and I decided not to try and squeeze in our other wires, and instead just use the hole in the firewall and put our wires through the rubber gasket.  We used a very small drill to poke our needed number of holes in the gasket and pushed the wires through after taping the ends with the black electrical tape (I have no idea the proper name for this stuff).

 With the wires in.

 

 

 

The last item (besides the solar panel wiring, which I'll address next) under the hood was the switch to merge the second battery into the main circuit.  We used a fused 18 gauge wire and mounted it, you guessed it, to the 2nd battery tray.

 

 

 

#2-B, solar panel installation and wiring.

 

I'm going to skip the physical installation of the solar panels, you can see that in the first Wilbur post.  The Renogy kit I purchased came with all the appropriate wiring, and connectors to merge the two panels into a single pos+ and neg- connections.  I merged these where the panels were mounted on the hood and then cut the wire so there was enough to go under the hood as well as an additional 3m in case I wanted to set the panels on the ground or elsewhere, while still keeping them connected.  The spare length of cable I rolled up into a mesh bag and tied it to the solar panel frame.

 

 

The two wires I then ran from the panels along the passenger side edge of the factory rack and down the channel along the side of the windshield.  The two wires are wrapped in a loose loom and zip-tied at the top to the factory rack, but conveniently they fit snugly into the channel along the side of the windshield.  Over 5,000km later and they haven't budged a bit.  The wind pressure keeps them firmly in place and there is still plenty of room for water to run down when it's raining.

 

 

We did have a bit of difficult time figuring out how to get the two wires under the hood.  Eventually the easiest way (which has worked quite well, no leaks or issues so far) was to cut a small divot in the hard plastic ridge to allow the two wires to fit underneath the flexible rubber seal underneath the hood itself.  We used an exacto knife to cut the divot in the ridge and fit the wires through.  We didn't use anything to keep them in place except about 6 inches further inside the hood, where they are zip-tied to the side.  So far (5,000km+) they haven't moved at all and seem to be doing just fine.

 

 

The pos+ wire went through a fuse, which we mounted (bet you can't guess!) to the 2nd battery tray and then the wires went through to the glove box area and charge controller.  The neg- ground wire went directly through to the controller.

 

 

As for bringing the wires through the glove box area, that was rather simple if time consuming.  I removed the glove box (five minutes) and found a loom to keep the wires together we were bringing in from the hood area.  Bringing them in slowly took about fifteen minutes and fitting them into the loom was another few minutes.  I only put the glove box back on after everything was hooked up and running.

 

#2-C) hooking everything together with the charge controller.

 

From the controller, there are six connections.  Pos+ and neg- from solar panels, pos+ and neg- to the power circuit (i.e. battery and vehicle electric), temperature sensor for the battery and current sensor directly to the battery.  To mount the controller we had to do a bit of figuring; if we wanted to use the included Renogy Adventurer controller (and I did, even though it was bigger than specialized automotive/marine controllers) we needed to make some sort of manual mount.

 

 

We took an old curtain rod and plasti-coated it to make an "L" shape that connected to an existing bolt under the dash.  Then to mount the controller itself we decided on a piece of Lexan ($5), to which we screwed the controller and drilled holes for the wires to go through.  Finally we put small U-shaped hooks on top to "hang" it on the curtain rod mount and plasti-coated the sides and mounts.  Finally we screwed on small mounts for the wires to prevent them from flexing too much when we moved the controller around.

 

 

After the curtain rod was installed and the controller was mounted on the Lexan frame and put in place, it was time to connect everything!  Basically we followed the instructions in the Renogy kit.  Put in the fuses for the connections to the charge controller.  It turned on, we checked settings, all good.  Then we plugged in the solar panels.  Bingo.  Everything worked!

 

 

As reference, we honestly probably just needed a single solar panel and a smaller battery.  On a clear and sunny day, the panels should charge (from 0) our main battery in an hour or less.  It's rather stupid how well it works, but for me I really enjoy having the peace of mind.  We have actively tried to deplete our battery (such as running our slow cooker, inverter and fridge together all day) but thus far haven't succeeded.  We've had Wilbur parked in a garage for a few days at a time with Freezy running and the battery hasn't dropped below 70%. 


I'm sure one day we will run out of power, but for now it's working great for how we use it.

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